The present invention relates to a tube bending machine, and more particularly to a tube feeding device for removing a tube from a tube magazine and transporting this tube to the bending machine.
Metallic tubes to be bent in tube bending machines are delivered to the bending machine from a magazine from which one individual tube is removed and transported to the bending machine in a direction transverse to the elongation of the tube. In the known devices, in order to provide the transportation of the tubes to be treated in the bending machine, a chute having relatively strong inclination is utilized to receive tubes from the magazine, in which chute tubes are positioned one after another. In this known device it was necessary to preliminarily separate an individual tube from a stock and then to feed the tubes to the chute. Since the tubes in the magazine were positioned in a stack each individual tube should have been separated from the stock by hand which was time consuming. The removing of a relatively large tube by hand was found physically exhausting for an operator.
In practice where rational manufacturing of tubes is required, a mechanical removal of individual tubes from the tube magazine is absolutely necessary. It has been observed that individual tubes stored in a stack in the tube magazine may be easily stuck to each other and thereby form the so-called bridge when the tubes are superposed one another. Under such conditions, it is rather difficult to separate an individual tube from the stock and remove it from the magazine.
There are known devices, in which hydraulically or pneumatically operated sliders positioned in the bottom area of the device are utilized. These sliders move the tubes in a direction transverse to the direction of elongation of the tubes located in the magazine. One of the tubes delivered by the slider falls into a recess provided in the area adjacent the slider. In operation of the known device an axial force caused by a loading cylinder and applied to a tube positioned in the recess when the tube is removed from the recess may cause bending or deforming of tubes being removed. Under these circumstances there is a danger that tubes being processed may be deformed or stuck in the tube magazine.